Add GetLastStateChange function

Author: ffenix113

state_change_log.go

@@ -48,6 +48,20 @@ func GetStateChangeLogs(model interface{}, db *gorm.DB) []StateChangeLog {
 	return changelogs
 }
 
+// GetLastStateChange gets last state change
+func GetLastStateChange(model interface{}, db *gorm.DB) *StateChangeLog {
+	var (
+		changelog StateChangeLog
+		scope      = db.NewScope(model)
+	)
+
+	db.Where("refer_table = ? AND refer_id = ?", scope.TableName(), GenerateReferenceKey(model, db)).Last(&changelog)
+	if changelog.To == "" {
+		return nil
+	}
+	return &changelog
+}
+
 // ConfigureQorResource used to configure transition for qor admin
 func (stageChangeLog *StateChangeLog) ConfigureQorResource(res resource.Resourcer) {
 	if res, ok := res.(*admin.Resource); ok {

transition_test.go

@@ -87,6 +87,35 @@ func TestStateTransition(t *testing.T) {
 	}
 }
 
+func TestGetLastStateChange(t *testing.T) {
+	order := &Order{}
+
+	if err := getStateMachine().Trigger("checkout", order, db, "checkout note"); err != nil {
+		t.Errorf("should not raise any error when trigger event checkout")
+	}
+
+	if err := getStateMachine().Trigger("pay", order, db, "pay note"); err != nil {
+		t.Errorf("should not raise any error when trigger event checkout")
+	}
+
+	if order.GetState() != "paid" {
+		t.Errorf("state doesn't changed to paid")
+	}
+
+	var lastStateChange = transition.GetLastStateChange(order, db)
+	if lastStateChange.To != "paid" {
+		t.Errorf("state to not set")
+	} else {
+		if lastStateChange.From != "checkout" {
+			t.Errorf("state from not set")
+		}
+
+		if lastStateChange.Note != "pay note" {
+			t.Errorf("state note not set")
+		}
+	}
+}
+
 func TestMultipleTransitionWithOneEvent(t *testing.T) {
 	orderStateMachine := getStateMachine()
 	cancellEvent := orderStateMachine.Event("cancel")